Screw cap comprising a tamper-evident band

ABSTRACT

At least one cutting element on a closure having a spout and a screw cap, which can be screwed thereon and which has a tamper-evident band. The tamper-evident band is joined to a lower edge of an outer wall of the screw cap via specified rupture location bridges. The at least one cutting element outwardly projects through an intermediate space. When the screw cap is unscrewed for the first time, the at least one cutting element cuts through the specified rupture location bridges. A distance between the tamper-evident band upper edge and the lower edge of the screw cap is provided with a measure whereby enabling the distance to be surmounted only occurs once all specified rupture location bridges are cut through.

[0001] The present invention relates to a receptacle with a closure,consisting of a screw cap with an inner thread and with a guaranteestrip without a tear-open tab, which is fastened to the screw cap and isconnected via break-off bridge locations, wherein the receptaclecomprises a cylindrical pour-out with an outer thread in which the screwcap is held.

[0002] Screw caps of the initially mentioned type have been known formany years. Their shaping tends to be dependent on the material fromwhich the receptacle on which the closure is placed is manufactured.With glass bottles, the pour-out is usually standardised and the rotaryclosures must normally correspond to the standard. With receptacles ofplastic the pour-out may be varied much more freely. Even withreceptacles of so-called soft material one applies pour-outs of plasticfastened thereon, which in turn may be manufactured with great freedomwith regard to shaping. The invention relates to screw caps whichcooperate with receptacles of plastic or soft material, whose pour-outis manufactured of plastic and wherein the screw cap and the pour outare matched to one another.

[0003] In the present case only screw caps with a guarantee strip whichmay be opened alone by rotating the screw cap are of interest, whereinsimultaneously the guarantee strip is separated from the screw cap.Embodiment forms of such closures are to be deduced for example fromDE-A-31 11 692, EP-B-0'149'496, EP-B-0'460'577, EP-B-0'593'396 or fromEP-B-0'625'950.

[0004] The manufacture of such screw caps with a guarantee strip is aproblem. On manufacture the core must be torn out of the screw capwithout at the same time the undercuts in the region of the break-offbridge locations leading to the guarantee strips being separated fromthe screw caps already on removal from the mould. It is however indeedthe case that these fragile locations are relatively often destroyedduring the manufacture. This leads to production interruption and to arejection of the manufactured closures. In order to reduce the danger ofdestruction one needs to provide relatively many break-off locations.The result of this is a difficult opening of the screw cap. As is known,on screwing open, all break-off locations are uniformly loaded intension, so that the forces sum and their result is directly related tothe number of required break-off locations.

[0005] The break-off locations are of course designed extraordinarilythin. The alignment of the molecule chains is therefore effected intheir region. These molecule chains which are now orientated in therunning direction of the break-off webs now have their highestresistance force precisely in this running direction. In other words theforces occurring on screwing open run practically axially to thepour-out direction and thus precisely in the running direction of thebreak-off locations. Added to this is the known effect that on screwingopen the tension forces are increased relatively slowly, wherein astretching of material is effected which effects a further alignment ofthe molecule chains and an increased tear strength.

[0006] In order to reduce the danger of destruction of the guaranteering or of the guarantee strip on removal from the mould one alsoapplies injection [moulding] tools with sliders. This however leads toextraordinarily expensive tools.

[0007] In order to avoid these problems, in DE-A-31 00 629 there issuggested a screw cap with a guarantee strip with which the guaranteestrip is initially integrally formed on the screw cap over the wholewall and the break-off line is only produced retrospectively by way ofsuitable cutting whilst leaving the break-off webs. Such closures areconsiderably easier to open and may be produced with practically norejects. The manufacture is however enormously expensive already alonedue the two-step manufacture. Accordingly such closures may hardly beobtained any more on the market.

[0008] From that which has been previously discussed it is clear thatone may best sever the webs or bridges of the break-off locationsbetween the screw cap and guarantee strip by forces which act in ashearing manner. This principle until today is only realised with screwclosures with which the guarantee strip is torn away by way of a tab.

[0009] It is therefore the object of the present invention to provide ascrew cap of the initially mentioned type which may be screwed on withconsiderably less force without having to accept the disadvantages ofthe known embodiment forms.

[0010] This object is achieved by the present invention with thefeatures of patent claim 1. Further advantageous embodiment forms are tobe deduced from the dependent claims and their effect and significanceis explained by way of the following description with reference to theaccompanying drawing.

[0011] One preferred embodiment example is shown in the drawing. Thereare shown in:

[0012] FIG. 1 a lateral view of the screw cap closure according to theinvention with which the pour-out is a separate part which is providedwith a flange and may be placed on a receptacle and

[0013] FIG. 2 the pour-out able to be placed onto a receptacle, alone ina view from above.

[0014] FIG. 3 shows an axial vertical section through the screw cap asshown in FIG. 1, omitting the pour-out, and

[0015] FIGS. 4 to 7 schematically show the various possible arrangementsof the cutting elements and the break-off bridge locations.

[0016] With the closure of interest here it is the case of a screwclosure with which the pour-out is integrally formed or attached on thereceptacle, wherein the closure as a result consists of a screw cap,provided with an inner thread and with a guarantee strip which isconnected to the screw cap via break-off bridge locations and which hasno tear-open tab.

[0017] The receptacle B, as shown in FIG. 1, may be a plastic bottle ora receptacle of soft material, specifically a flexible bag [tubing]which consists of a multi-layered film of various materials. Suchmulti-layered, laminated film materials for example consist of a paperor cardboard layer which is configured laminated with several layerswith plastic films and an aluminium film ply. The pour-out in the formof a cylindrical bung is adhered or welded on such a receptacle of softmaterial. If with the receptacle B it is the case of a plastic bottle,then this bung is formed by the bottle neck. The bung 1 has a flange 2and a cylindrical pour-out which is provided with an outer thread 4. Ascrew cap 5 may be fastened on the cylindrical pour-out 3 with the outerthread 4. The screw cap 5 has an upper cover surface 6 to which at theedge an outer wall 7 connects in a circumferential manner. The outerwall 7 cylindrically formed at least on the inner surface comprises aninner thread 8 on the inner surface. A guarantee strip is integrallyformed on the lower edge of the screw cap 5, or on the lower edge of theouter wall 7 via a multitude of break-off bridge locations 10, theguarantee strip 11 has the shape of a conical ring. The break-offbridges 10 bridge the distance a between the lower edge 12 of the cap 5and the upper edge 13 of the guarantee strip 11. Thus in each casebetween two adjacent break-off bridge locations 10 and the two mentionededges there remain intermediate spaces 14.

[0018] In order to improve the grip of the screw cap, the outer wall 7comprises a suitable corrugation or knurling 9.

[0019] The special design of the bung 1 or of the bottle neck is nowexplained with reference to FIG. 2. Whilst in FIG. 1 the screw cap 5 isunambiguously fastened on a receptacle in the form of a plastic bottle,in FIG. 2 there is shown a bung as in particular may be attached to softpackagings. The bung 1 consists of a cylindrical pour-out 3 on whoselower edge a circular flange is integrally formed. With a correspondingconfiguration of a receptacle of plastic, a collar 2′ corresponds to theflange 2. Whilst the flange serves mainly for fastening the bung 1 onthe soft packaging, the collar 2′ in particular is to ensure that onemay not manipulate the guarantee strip by way of griping below theguarantee strip. In the correctly assembled condition the guaranteestrip 11 in the case of a plastic receptacle lies at least approximatelyon the collar 2′ whilst with the version of a soft packaging theguarantee strip 11 comes to lie on the mentioned flange 2. Above theflange 2 on the cylindrical pour-out 3 there is integrally formed aretaining collar 15. The diameter of the retaining collar 15 correspondsapproximately to the inner diameter of the screw cap in the region ofthe lower edge 12. At least one cutting element 20 is integrally formedon this retaining collar 15. The retaining collar 15 is provided withsupport cams 16 which engage into the mentioned intermediate spaces 14.The cutting elements 20 likewise protrude radially outwards through theintermediate spaces. The cutting elements 20 however protrude furtheroutwards than the support cams 16 which project outwards only extremelyslightly and do not come into contact with the break-off bridgelocations 10 during the screwing-off movement of the screw cap. Thesupport cams, as their name indicates, have the function of supportingthe screw cap at the correct height during assembly. The screw cap 5 hasan inner thread 8 which is designed as a fine thread just as the outerthread 4 of the cylindrical pour-out 3. This permits the screw cap 5 tobe assembled by simply abutting together, wherein the two threads slideover one another in the manner of a ratchet. In order to ensure thatwith this manner of assembly the guarantee strip 11 is not immediatelypressed onto the flange 2 or the collar 2′ and that with this thebreak-off bridge locations are not destroyed already on assembly, thesupport cams 16 may accommodate these forces. The retaining collar 15itself is in turn connected to the flange 2 or the collar 2′ by way ofsupport struts 17. The collar 2′ may of course again by supported withrespect to the receptacle B. This however is not shown here in thedrawing. Not being essential for the actual invention, on the flangethere is attached an orientation marking 18 which serves for positioningthe bung on assembly. The mentioned orientation marking permits analignment of the bung with suitable machines, whereupon the screw cap 5which likewise may be provided with orientation means not shown here,may then be joined together in a predefined angular position relative toone another, and then, as already mentioned, may be assembled by a purepressing onto one another. Thus for example it is ensured that with suchan assembly the cutting elements get exactly into the intermediatespaces 14.

[0020] The configuration of the cutting elements 20 or possibly of thesingle cutting element 20 advantageously has the shape of a fin or asaw-tooth. The edge 21 lying at the front in the screw-off direction,subsequently called the front edge runs inclined to the radial directionin a manner such that when unscrewing the front edge pulls the break-offbridge locations from the outside towards the centre and separatesthese. The edge 22 at the front in the screwing-on direction, which mayalso be called the rear edge, runs roughly parallel to the front edge21. If one does not assemble the screw cap according to the invention aspreviously described by way of a purely axial abutting together, but byscrewing on, then this rear edge 22 acts as a deflector and mayelastically outwardly deform the break-off bridge locations without aseparation occurring at the same time. The formation of the cuttingelements 20 as a fin thus effects the possibility of various assemblymethods. So that this is correctly possible, the conically outwardlyprojecting guarantee strip 11 with its lower outwardly projecting edge19 must project so far outwards that when screwing-on the fin-likecutting element 20 indeed comes to run below the guarantee strip.

[0021] As already mentioned, in the assembled condition advantageouslythe cutting elements 20 and the support cams 16 bear on the lower edge12 of the outer wall 7. Optimally one would provide the inner thread 8and the outer thread 4 with a gradient which is so small that the lowerside of the cutting element 20 only comes to bear on the upper edge 13of the guarantee strip 11 when already all break-off bridge locations 10have been severed. In the example according to FIG. 1 to 3 this is equalto a rotation of the screw cap 5 by about 180°. This angle is of coursedependent on how many cutting elements 20 are present and how theirdistribution on the circumference is. The distribution of the break-offbridge locations 10 on the circumference also determines the rotationangle which is required for severing all break-off locations.

[0022] These possibilities of the arrangement for the cutting elementsand the break-off bridge locations 10 are now dealt with in more detail.With regard to this the FIGS. 4 to 7 are referred to. In the simplestform a single cutting element 20 may be present and the break-offlocations in this case are separated after one another in the directionof the rotation of the screw cap, as the indicated numbering hereexplains. In contrast to this simplest embodiment form according to FIG.4, a second variant is shown in FIG. 5. In this variant there arepresent two cutting elements 20. Just as in FIG. 4 the break-off bridgelocations 10 are arranged uniformly distributed on the circumference.The two fin-like cutting elements here are not attached exactlydiametrically opposite one another but are displaced slightly by anangle. By way of this it is achieved that alternately always firstly theone and thereafter the other cutting element steps into function, bywhich means by way of half a rotation all break-off bridge locations aresevered. Thanks to the displaced arrangement of the cutting elements,for opening this variant practically the same force effort is requiredas with the embodiment according to FIG. 4. It is however quite possibleto indeed arrange the cutting elements diametrically opposite oneanother so that two break-off locations lying diametrically opposite oneanother are always simultaneously severed. In this case the force effortwould be practically double as high as with the embodiment according tothe solution specified here.

[0023] In the embodiment variant according to FIG. 6 again there arepresent two cutting elements, but in contrast to the embodimentaccording to FIG. 5 the break-off bridge locations are distributedirregularly on the circumference so that the bridges are severed in thesequence shown here by way of example.

[0024] Finally in FIG. 7 there is shown yet a further variant with whichthree cutting elements are arranged at uniform distances and betweenthese there are present in each case three break-off bridge locations atuniform distances between in each case two adjacent cutting elements. Inthis case the closure may released from the guarantee strip already witha third rotation. The force effort with this however is about threetimes as much as with the variant with which in each case only onebridge is severed simultaneously. Of course it would also be possiblewith this solution to arrange the break-off bridge locations irregularlyor to integrally form the cutting elements in each case displaced by asmall angle, so that here it would again be ensured that always only onebreak-off bridge location is destroyed simultaneously.

List of Reference Numerals

[0025]1. bung

[0026]2. flange

[0027]2′. collar

[0028]3. pour-out, cylindrical

[0029]4. outer thread

[0030]5. screw cap

[0031]6. upper cover surface

[0032]7. outer wall

[0033]8. inner thread

[0034]9. knurling

[0035]10. break-off bridge locations

[0036]11. guarantee strip

[0037]12. lower edge of the screw cap

[0038]13. upper edge of the guarantee strip

[0039]14. intermediate space

[0040]15. retaining collar

[0041]16. support cams

[0042]17. support struts

[0043]18. orientation mark

[0044]19. lower edge of the guarantee strip

[0045]20. cutting element

[0046]21. front edge

[0047]22. rear edge

1. A receptacle (B) with a closure comprising: a screw cap (5) having aninner thread (8) and a guarantee strip (11) without a tear-open tab,fastened to the screw cap (5) and connected via break-off bridgelocations (10), the receptacle having a cylindrical pour-out (3) with anouter thread (4) on which the screw cap (5) is held, on the pour-out (3)there being integrally formed at least one cutting element (20) which ina virgin condition of the closure projects at least approximatelyradially outwards through and between two adjacent break-off bridgelocations (10).
 2. A receptacle with a closure according to claim 1,wherein an outer thread and an inner thread (4, 8) have a heightdifference between a guarantee strip upper edge (13) and a screw caplower edge (12) that is overcome after the at least one cutting element(20) has severed all of the break-off bridge locations (10).
 3. Areceptacle (B) with a closure according to claim 1, wherein there are atleast two cutting elements, which are radially displaced by a multipleplus a fraction of a distance (D) between neighboring break-off bridgelocations (10), and on rotating the screw cap (5) only one of the atleast one cutting element (20) contacts a break-off bridge location (10)to be separated, and all break-off bridge locations (10) are severed oneafter the other (FIG. 5).
 4. A receptacle (B) with a closure accordingto claim 1, wherein at least two cutting elements (20) are distributedon a circumference at a regular distance to one another, the break-offbridge locations (10) are irregularly distributed on the circumferenceso that on rotating the screw cap (5) only one of the at least onecutting element is in (20) contacts a break-off bridge location (10) tobe separated, and all of the break-off bridge locations (10) are severedone after the other.
 5. A receptacle (B) with a closure according toclaim 1, wherein there are more than two of the cutting elements (20)and maximally two of the cutting elements (20) simultaneously contactone of the at least one break-off bridge location (10).
 6. A receptacle(B) with a closure according to claim 1, wherein there are at leastthree of the cutting elements (20) and maximally three of the cuttingelements (20) are simultaneously in contact with one of the at least onebreak-off bridge location (10).
 7. A receptacle (B) with a closureaccording to claim 1, wherein the break-off bridge locations (10) taperfrom a guarantee strip upper edge (13) towards a screw cap lower edge(12) in a pointed manner.
 8. A receptacle (B) with a closure accordingto claim 1, wherein the at least one cutting element (20) in anassembled condition, before opening for a first time, at leastapproximately bears on a lower edge (12) of the screw cap (5).
 9. Areceptacle (B) with a closure according to claim 1, wherein in additionto the at least one cutting element (20) further radially outwardlydirected support cams (16) are integrally formed on the pour-out (3),which support the screw cap (5) on assembly.
 10. A receptacle (B) with aclosure according to claim 1, wherein a guarantee strip (11) from thescrew cap edge (12) is shaped conically outwards and widens downwards.11. A receptacle (B) with a closure according to claim 10, wherein alower outwardly projecting edge (19) of the guarantee strip projectsoutwards at least equally as far as the at least one cutting element(20) projects outwards in a radial direction.
 12. A receptacle (B) witha closure according to claim 1, wherein the at least one cutting element(20) has a shape of one of a fin and a saw-tooth, with an edge (21)lying at a front in a screwing-off direction and runs inclined to aradial direction so that on screwing off, an edge pulls and severs thebreak-off bridge locations (10) from an outside towards a center and asecond edge (22) which is at the front in the screwing-on direction isinclined to the radial direction so that on screwing on the break-offbridge locations (10) are deformed elastically outwards withouteffecting a separation being effected.
 13. A receptacle (B) with aclosure according to claim 1, wherein the screw cap (5) and the pour-out(3) each comprise a positioner (18) which determines a radial alignmentof the two parts to one another and permits an assembly by axiallyabutting together the screw cap (5) and pour-out (3), with which thethreads (4, 8) are knocked over one another.